This would be a purchase from a private party. I guess that I need to assume that nothing will be accessible, unless I get lucky. I was hoping that there was a way to transfer the license to my as yet to be created PSN account.
If their account is on there, even if you don't have access on it, you can still use their games. So they could change their password so you'd never be able to login as them, but as long as their account is on there, you can play THEIR games on YOUR account.